Foxpro callers have these calls in there callers and they work but only in the mating season but if you have a fox that turns and runs if you play the call most times they stop and give you a chance for a shot.

The only reason I see for them to circle down wind is when they are curious but something does not seem wright to them.
The best night to call foxes are cold and windy I have had them come to a few feet away.
The guy that calls and lamps when I am shooting called 2 foxes at the same time from two ends of the same feild I shot 1 at 25yds and the other one was that close all I could see through a 6x50 scope was a foxes head totaly out of focus so I put the cross hairs where I though its eyes should be and squose the trigger 2 dead foxes with 2 shots.